The Clinical and Biochemical Predictors of Bone Mass in Preterm Infants

BackgroundMetabolic bone disease of prematurity still occurs in preterm infants, although a significant improvement in neonatal care has been observed in recent decades. Dual-energy X-ray absorptiometry (DXA) is the precise technique for assessing bone mineral content (BMC) in preterm infants, but is not widely available.AimTo investigate the clinical and biochemical parameters, including bone metabolism markers as potential predictors of BMC, in preterm infants up to 3 months corrected age (CA).ResultsThe appropriate quality DXA scans were available for 160 infants (87%) examined at term and for 130 (71%) tested at 3 mo CA. Higher iPTH level was the only independent predictor of lower BMC at term, whereas lower BMC at 3 mo CA was associated both with lower urinary phosphate excretion and higher serum osteocalcin level. ROC analysis showed that iPTH >43.6 pg/mL provided 40% sensitivity and 88% specificity in identification of preterm infants with lower BMC at term. In turn, urinary phosphate excretion (TRP>97% or UP/Cr ≤0.74 mg/mg) and serum osteocalcin >172 ng/mL provided 40% sensitivity and 93% specificity in identification of infants with decreased BMC at 3 mo CA.ConclusionSerum iPTH might to be a simple predictor of reduced BMC in preterm infants at term age, but urinary phosphate excretion and serum osteocalcin might predict reduced BMC at 3 mo CA. These results represent a promising diagnostic tool based on simple, widely available biochemical measurements for bone mass assessment in preterm infants.     

Aged-Related Changes in Body Composition and Association between Body Composition with Bone Mass Density by Body Mass Index in Chinese Han Men over 50-year-old

Objectives

Aging, body composition, and body mass index (BMI) are important factors in bone mineral density (BMD). Although several studies have investigated the various parameters and factors that differentially influence BMD, the results have been inconsistent. Thus, the primary goal of the present study was to further characterize the relationships of aging, body composition parameters, and BMI with BMD in Chinese Han males older than 50 years.

Methods

The present study was a retrospective analysis of the body composition, BMI, and BMD of 358 Chinese male outpatients between 50 and 89 years of age that were recruited from our hospital between 2009 and 2011. Qualified subjects were stratified according to age and BMI as follows: 50–59 (n = 35), 60–69 (n = 123), 70–79 (n = 93), and 80–89 (n = 107) years of age and low weight (BMI: < 20 kg/m²; n = 21), medium weight (20 ≤ BMI < 24 kg/m²; n = 118), overweight (24 ≤ BMI < 28 kg/m²; n = 178), and obese (BMI ≥ 28 kg/m²; n = 41). Dual-energy X-ray absorptiometry (DEXA) was used to assess bone mineral content (BMC), lean mass (LM), fat mass (FM), fat-free mass (FFM), lumbar spine (L1-L4) BMD, femoral neck BMD, and total hip BMD. Additionally, the FM index (FMI; FM/height²), LM index (LMI; LM/height²), FFM index (FFMI; [BMC+LM]/height²), percentage of BMC (%BMC; BMC/[BMC+FM+LM] × 100%), percentage of FM (%FM; FM/[BMC+FM+LM] × 100%), and percentage of LM (%LM; LM/(BMC+FM+LM) × 100%) were calculated. Osteopenia or osteoporosis was identified using the criteria and T-score of the World Health Organization.

Results

Although there were no significant differences in BMI among the age groups, there was a significant decline in height and weight according to age (p < 0.0001 and p = 0.0002, respectively). The LMI and FFMI also declined with age (both p < 0.0001) whereas the FMI exhibited a significant increase that peaked in the 80-89-years group (p = 0.0145). Although the absolute values of BMC and LM declined with age (p = 0.0031 and p < 0.0001, respectively), there was no significant difference in FM. In terms of body composition, there were no significant differences in %BMC but there was an increase in %FM (p < 0.0001) and a decrease in %LM (p < 0.0001) with age. The femoral neck and total hip BMD significantly declined with age (p < 0.0001 and p = 0.0027, respectively) but there were no differences in L1-L4. BMD increased at all sites (all p < 0.01) as BMI increased but there were declines in the detection rates of osteoporosis and osteopenia (both p < 0.001). A logistic regression revealed that when the medium weight group was given a BMI value of 1, a decline in BMI was an independent risk factor of osteoporosis or osteopenia, while an increase in BMI was a protective factor for BMD. At the same time, BMD in L1-L4 exhibited a significant positive association with FMI (p = 0.0003) and the femoral neck and total hip BMDs had significant positive associations with FFMI and LMI, respectively (both p < 0.0001).

Conclusions

These data indicate that LMI and FFMI exhibited significant negative associations with aging in Chinese Han males older than 50 years, whereas FMI had a positive association. BMD in the femoral neck and total hip declined with age but an increased BMI was protective for BMD. LMI and FFMI were protective for BMD in the femoral neck and total hip.     

Lack of CD47 Impairs Bone Cell Differentiation and Results in an Osteopenic Phenotype in Vivo due to Impaired Signal Regulatory Protein α (SIRPα) Signaling

Here, we investigated whether the cell surface glycoprotein CD47 was required for normal formation of osteoblasts and osteoclasts and to maintain normal bone formation activity in vitro and in vivo. In parathyroid hormone or 1α,25(OH)₂-vitamin D3 (D3)-stimulated bone marrow cultures (BMC) from CD47^−/− mice, we found a strongly reduced formation of multinuclear tartrate-resistant acid phosphatase (TRAP)⁺ osteoclasts, associated with reduced expression of osteoclastogenic genes (nfatc1, Oscar, Trap/Acp, ctr, catK, and dc-stamp). The production of M-CSF and RANKL (receptor activator of nuclear factor κβ ligand) was reduced in CD47^−/− BMC, as compared with CD47^+/+ BMC. The stromal cell phenotype in CD47^−/− BMC involved a blunted expression of the osteoblast-associated genes osterix, Alp/Akp1, and α-1-collagen, and reduced mineral deposition, as compared with that in CD47^+/+ BMC. CD47 is a ligand for SIRPα (signal regulatory protein α), which showed strongly reduced tyrosine phosphorylation in CD47^−/− bone marrow stromal cells. In addition, stromal cells lacking the signaling SIRPα cytoplasmic domain also had a defect in osteogenic differentiation, and both CD47^−/− and non-signaling SIRPα mutant stromal cells showed a markedly reduced ability to support osteoclastogenesis in wild-type bone marrow macrophages, demonstrating that CD47-induced SIRPα signaling is critical for stromal cell support of osteoclast formation. In vivo, femoral bones of 18- or 28-week-old CD47^−/− mice showed significantly reduced osteoclast and osteoblast numbers and exhibited an osteopenic bone phenotype. In conclusion, lack of CD47 strongly impairs SIRPα-dependent osteoblast differentiation, deteriorate bone formation, and cause reduced formation of osteoclasts.     

Radial bone mineral content of normal Japanese infants and prepubertal children: influence of age,sex and body size

The present study was performed to measure appendicular bone mass of Japanese infants and children, and to assess the influence of age, sex and body size on bone mass during the period of bone growth. The bone mineral content (BMC) and bone width (BW) at the distal third of the radius were measured by single photon absorptiometry (SPA) in 229 healthy Japanese infants and children aged 0–12 years, and the BMC/BW ratio was calculated to give the bone mineral density (BMD). BMC and BW increased with age until 2 years, while BMD did not obviously change until 2 years. After 2 years of age, the overall effect of aging appeared more prominent in BMC and BMD than in BW. There were no significant differences in BMC, BW and BMD between males and females aged 0–12 years. Age, body height, and body weight were strongly correlated with three parameters of bone mass (BMC, BW, and BMD). Among the three parameters of bone mass, BMC showed the highest Pearson coefficient of correlation with age (r = 0.955), body height (r = 0.957) and body weight (r = 0.966), as compared with BW and BMD. The present cross-sectional study provides normative data of the appendicular bone mass in healthy Japanese children, which may serve as a standard for assessment of bone mineralization in Japanese infants and children with medical problems.     

Polymorphisms in the low-density lipoprotein receptor-related protein 5 (LRP5) gene are associated with variation in vertebral bone mass, vertebral bone size, and stature in whites

Stature, bone size, and bone mass are interrelated traits with high heritability, but the major genes that govern these phenotypes remain unknown. Independent genomewide quantitative-trait locus studies have suggested a locus for bone-mineral density and stature at chromosome 11q12-13, a region harboring the low-density lipoprotein receptor–related protein 5 (LRP5) gene. Mutations in the LRP5 gene were recently implicated in osteoporosis-pseudoglioma and “high-bone-mass” syndromes. To test whether polymorphisms in the LRP5 gene contribute to bone-mass determination in the general population, we studied a cross-sectional cohort of 889 healthy whites of both sexes. Significant associations were found for a missense substitution in exon 9 (c.2047G→A) with lumbar spine (LS)–bone-mineral content (BMC) (P=.0032), with bone area (P=.0014), and with stature (P=.0062). The associations were observed mainly in adult men, in whom LRP5 polymorphisms accounted for 15% of the traits’ variances. Results of haplotype analysis of five single-nucleotide polymorphisms in the LRP5 region suggest that additional genetic variation within the locus might also contribute to bone-mass and size determination. To confirm our results, we investigated whether LRP5 haplotypes were associated with 1-year gain in vertebral bone mass and size in 386 prepubertal children. Significant associations were observed for changes in BMC (P=.0348) and bone area (P=.0286) in males but not females, independently supporting our observations of a mostly male-specific effect, as seen in the adults. Together, these results suggest that LRP5 variants significantly contribute to LS–bone-mass and size determination in men by influencing vertebral bone growth during childhood.     

Does Vitamin D affects changes in volumetric bone mineral density and architecture in postmenopausal women after conservatively treated distal radius fractures?

Objective:We examined the role of vitamin D on volumetric bone mineral density (vBMD) and architecture during the first week’s post-fracture in postmenopausal women (PMW) with distal radial fractures (DRF) treated conservatively using peripheral Quantitative Computed Tomography (pQCT).Methods:Patients were classified into 2 groups according to initial median 25(OH)D level; Group A (25(OH)D ≥15 ng/ml) and group B (25(OH)D <15 ng/ml). All patients were followed for 12 weeks at three visits: baseline, 6 weeks and 12 weeks post fracture. pQCT was performed at baseline in fractured and contralateral non-fractured radius and at 6^th and 12^th week on the fractured side.Results:39 patients completed the protocol. Mean 25(OH)D levels were 15.60±7.35 ng/ml (3.5-41.7). Trabecular (trab) bone mineral content (BMC) and trabvBMD increased at 6 wk. vs. baseline (p<0.001). Cortical BMC, cortvBMD and cross- sectional area (CSA) progressively decreased (p<0.001) during the 12 weeks. There was no interaction between baseline 25(OH)D levels and changes in trabecular and cortical BMC, vBMD and CSA. Advanced age and higher CTX and P1NP were associated with higher cortical bone loss.Conclusion:Vitamin D deficiency does not affect the early architectural changes after a DRF. Advanced age and higher bone remodeling were associated with higher cortical bone loss, probably related to immobilization and independent of vitamin D levels.     

Body Composition and Body Weight: Criteria of Overnutrition

The terms “body weight” and “body composition” are by no means synonymous, and attention is increasingly being focused on body composition. A measurement of relative fatness is a better criterion of caloric overnutrition than is body weight.The simple technique of skinfold measurement using established standard methods is the most practical for use in the field to obtain an estimate of fatness or caloric overnutrition. The current need is for the establishment of “norms” for skinfolds for population groups of all ages and both sexes. When these are established, excellent simple criteria for overnutrition will be available.Prior to the establishment of norms, more work is needed to indicate which skinfolds for each age group and for each sex best reflect total body fatness. Body fatness may then be studied in relation to body weight and both may be related to morbidity, mortality and longevity. Finally, the answer may be obtained to the question whether it is overweight per se or overfatness that is related to excess morbidity and mortality.     

Infection Density Dynamics of the Citrus Greening Bacterium “Candidatus Liberibacter asiaticus” in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants

Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, “Candidatus Liberibacter asiaticus,” and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of “Ca. Liberibacter asiaticus” in field populations of D. citri with experiments using field-collected insects to address how “Ca. Liberibacter asiaticus” infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from “Ca. Liberibacter asiaticus”-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were “Ca. Liberibacter asiaticus” positive. The infections were systemic across head-thorax and abdomen, ranging from 10³ to 10⁷ bacteria per insect. In spring, the infection densities were low in March, at ∼10³ bacteria per insect, increasing up to 10⁶ to 10⁷ bacteria per insect in April and May, and decreasing to 10⁵ to 10⁶ bacteria per insect in late May, whereas the infection densities were constantly ∼10⁶ to 10⁷ bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with “Ca. Liberibacter asiaticus” infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected “Ca. Liberibacter asiaticus”-infected insects suggested that (i) “Ca. Liberibacter asiaticus”-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼10⁶ bacteria per insect) of “Ca. Liberibacter asiaticus” density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits “Ca. Liberibacter asiaticus” to citrus plants in a stochastic manner. These findings provide valuable insights into understanding, predicting, and controlling this notorious citrus pathogen.     

Direct Synthesis of Lamin A,Bypassing Prelamin A Processing,Causes Misshapen Nuclei in Fibroblasts but No Detectable Pathology in Mice

Lamin A, a key component of the nuclear lamina, is generated from prelamin A by four post-translational processing steps: farnesylation, endoproteolytic release of the last three amino acids of the protein, methylation of the C-terminal farnesylcysteine, and finally, endoproteolytic release of the last 15 amino acids of the protein (including the farnesylcysteine methyl ester). The last cleavage step, mediated by ZMPSTE24, releases mature lamin A. This processing scheme has been conserved through vertebrate evolution and is widely assumed to be crucial for targeting lamin A to the nuclear envelope. However, its physiologic importance has never been tested. To address this issue, we created mice with a “mature lamin A-only” allele (Lmna^LAO), which contains a stop codon immediately after the last codon of mature lamin A. Thus, Lmna^LAO/LAO mice synthesize mature lamin A directly, bypassing prelamin A synthesis and processing. The levels of mature lamin A in Lmna^LAO/LAO mice were indistinguishable from those in “prelamin A-only” mice (Lmna^PLAO/PLAO), where all of the lamin A is produced from prelamin A. Lmna^LAO/LAO exhibited normal body weights and had no detectable disease phenotypes. A higher frequency of nuclear blebs was observed in Lmna^LAO/LAO embryonic fibroblasts; however, the mature lamin A in the tissues of Lmna^LAO/LAO mice was positioned normally at the nuclear rim. We conclude that prelamin A processing is dispensable in mice and that direct synthesis of mature lamin A has little if any effect on the targeting of lamin A to the nuclear rim in mouse tissues.     

Puerperal Thromboembolic Disease in “High Risk” Cases

One hundred obstetric patients were studied for evidence of puerperal thromboembolic disease. Only one case of deep vein thrombosis was detected in patients thought to be in a “high risk” category because of age or operative intervention. Clinical findings were unreliable compared with measurements of ¹²⁵I-labelled fibrinogen uptake. Doppler ultrasound flow detection proved a simple screening technique but produced no abnormal findings in this series.     

The Therapeutic Effect on Bone Mineral Formation from Biomimetic Zinc Containing Tricalcium Phosphate (ZnTCP) in Zinc-Deficient Osteoporotic Mice

The aim of this study was to evaluate the therapeutic efficacy of biomimetic zinc-containing tricalcium phosphate (ZnTCP) produced by hydrothermally converting calcium carbonate exoskeletons from foraminifera, in the treatment of osteoporotic mice. X-Ray powder diffraction showed crystallographic structures matching JCPDS profile for tricalcium phosphate. Mass spectroscopy used to calculate total composition amount showed similar amount of calcium (5×10⁴ µg/g) and phosphate (4×10⁴ ppm) after conversion and the presence of zinc (5.18×10³ µg/g). In vitro zinc release showed no release in PBS buffer and <1% zinc release in 7 days. In vivo evaluation was done in ovariectomized mice by implanting the ZnTCP samples in the soft tissues near the right femur bone for four weeks. Thirty ddY mice (5 weeks old, average weight of 21 g) were divided into six experimental groups (normal, sham, OVX, β-TCP, ZnTCP and direct injection of zinc). CT images were taken every two weeks where the bone mineral density (BMD) and bone mineral content (BMC) were calculated by software based on CT images. The ZnTCP group exhibits cortical and cancellous bone growth of 45% and 20% respectively. While sham, OVX and β-TCP suffered from bone loss. A correlation was made between the significant body weight increase in ZnTCP with the significant increase in plasma zinc level compared with OVX. The presented results indicate that biomimetic ZnTCP were effective in preventing and treating bone loss in osteoporotic mice model.     

Immunofluorescence Flow Cytometry Technique for Enumeration of the Brown-Tide Alga, Aureococcus anophagefferens

A new immunologically based flow cytometry (IFCM) technique was developed to enumerate Aureococcus anophagefferens, a small pelagophyte alga that is the cause of “brown tides” in bays and estuaries of the mid-Atlantic states along the U.S. coast. The method utilizes a monoclonal antibody conjugated to fluorescein isothiocyanate (FITC-MAb) to label the surface of A. anophagefferens cells which are then detected and enumerated by using a flow cytometer. Optimal conditions for FITC-MAb staining, including solution composition, incubation times, and FITC-MAb concentrations, were determined. The FITC-MAb method was tested for cross-reactivity with nontarget, similarly sized, photoautotrophic protists, and the method was compared to an enzyme-linked immunosorbent assay (ELISA) using the same MAb. Comparisons of the IFCM technique to traditional microscopy enumeration of cultures and spiked environmental samples showed consistent agreement over several orders of magnitude (r² > 0.99). Comparisons of the IFCM and ELISA techniques for enumerating cells from a predation experiment showed a substantial overestimation (up to 10 times higher) of the ELISA in the presence of consumers of A. anophagefferens, presumably due to egested cell fragments that retained antigenicity, using the ELISA method, but were not characterized as whole algal cells by the IFCM method. Application of the IFCM method to environmental “brown-tide” samples taken from the coastal bays of Maryland demonstrated its efficacy in resolving A. anophagefferens abundance levels throughout the course of a bloom and over a large range of abundance values. IFCM counts of the brown-tide alga from natural samples were consistently lower than those obtained using the ELISA method and were equivalent to those of the polyclonal immunofluorescence microscopy technique, since both methods discriminate intact cells. Overall, the IFCM approach was an accurate and relatively simple technique for the rapid enumeration of A. anophagefferens in natural samples over a wide range of abundance values (10³ to 10⁶ cells ml⁻¹).     

Deletion of STAT5a/b in Vascular Smooth Muscle Abrogates the Male Bias in Hypoxic Pulmonary Hypertension in Mice: Implications in the Human Disease

Chronic hypoxia typically elicits pulmonary hypertension (PH) in mice with a male-dominant phenotype. There is an opposite-sex bias in human PH, with a higher prevalence in women, but greater survival (the “estrogen paradox”). We investigated the involvement of the STAT5a/b species, previously established to mediate sexual dimorphism in other contexts, in the sex bias in PH. Mice with heterozygous or homozygous deletions of the STAT5a/b locus in vascular smooth muscle cells (SMCs) were generated in crosses between STAT5a/b^fl/fl and transgelin (SM22α)-Cre^+/+ parents. Wild-type (wt ) males subjected to chronic hypoxia showed significant PH and pulmonary arterial remodeling, with wt females showing minimal changes (a male-dominant phenotype). However, in conditional STAT5^+/− or STAT5^−/− mice, hypoxic females showed the severest manifestations of PH (a female-dominant phenotype). Immunofluorescence studies on human lung sections showed that obliterative pulmonary arterial lesions in patients with idiopathic pulmonary arterial hypertension (IPAH) or hereditary pulmonary arterial hypertension (HPAH), both male and female, overall had reduced STAT5a/b, reduced PY-STAT5 and reduced endoplasmic reticulum (ER) GTPase atlastin-3 (ATL3). Studies of SMCs and endothelial cell (EC) lines derived from vessels isolated from lungs of male and female IPAH patients and controls revealed instances of coordinate reductions in STAT5a, STAT5b and ATL3 in IPAH-derived cells, including SMCs and ECs from the same patient. Taken together, these data provide the first definitive evidence for a contribution of STAT5a/b to the sex bias in PH in the hypoxic mouse and implicate reduced STAT5 in the pathogenesis of the human disease.     

The Prognostic Value of Peak Cardiac Power Output in Chinese Patients with Chronic Heart Failure

Background

Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO₂) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO₂. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO₂ in Chinese patients with CHF.

Methods

Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m² and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths.

Results

Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO₂,VE/VCO₂ slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO₂≤13.4 ml.kg^-1.min^-1, and VE/VCO₂ slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg^-1.min^-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05).

Conclusions

Peak CPO was not a predictor of cardiac death in Chinese CHF patients.     

Bone Morphogenetic Protein 6 Polymorphisms Are Associated with Radiographic Progression in Ankylosing Spondylitis

Background and Object

Nearly 25 genetic loci associated with susceptibility to ankylosing spondylitis (AS) have been identified by several large studies. However, there have been limited studies to identify the genes associated with radiographic severity of the disease. Thus we investigated which genes involved in bone formation pathways might be associated with radiographic severity in AS.

Methods

A total of 417 Korean AS patients were classified into two groups based on the radiographic severity as defined by the modified Stoke’ Ankylosing Spondylitis Spinal Score (mSASSS) system. Severe AS was defined by the presence of syndesmophytes and/or fusion in the lumbar or cervical spine (n = 195). Mild AS was defined by the absence of any syndesmophyte or fusion (n = 170). A total of 251 single nucleotide polymorphisms (SNPs) within 52 genes related to bone formation were selected and genotyped. Odds ratios (OR) and 95% confidence interval (95% CI) were analysed by multivariate logistic regression controlling for age at onset of symptoms, sex, disease duration, and smoking status as covariates.

Results

We identified new loci of bone morphogenetic protein 6 (BMP6) associated with radiographic severity in patients with AS that passed false discovery rate threshold. Two SNPs in BMP6 were significantly associated with radiologic severity [rs270378 (OR 1.97, p = 6.74×10⁻⁴) and rs1235192 [OR 1.92, p = 1.17×10⁻³]) adjusted by covariates.

Conclusion

This is the first study to demonstrate that BMP6 is associated with radiographic severity in AS, supporting the role wingless-type like/BMP pathway on radiographic progression in AS.     

Determination of the Pressure Drop Across an Arterial Stenosis Utilizing Angiocinedensitometry

A method is presented for an evaluation of the hemodynamic significance of a stenotic lesion in the arterial tree.Twenty-three patients were examined with arteriosclerosis obliterans and intermittent claudication of the same severity. Flow velocity data obtained by angiodensitometry and viscosity values calculated from the hematocrit were inserted into the Poiseuille''s flow formula to obtain the pressure drop across a stenotic lesion in the left external iliac artery. By the same way, the pressure gradient was calculated in 33 “normal” subjects.The normal pressure gradient along the external iliac artery varied between 23 to 110 dynes/cm² (52 ± 24 dynes/cm² for mean and S.d), and the normal resistance to flow was 6.08 ± 4.1 dyne sec/cm⁵).Stenotic lesions of similar dimensions gave widely varying pressure drops (114-4,736 dynes/cm²) (mean and S.d 1,309 ± 1,224 dynes/cm²) indicating a difference in the hemodynamic significance of the various lesions. These values were significantly different (p(t) < 0.001) from the normal values. The resistance across these stenotic lesions ranged between 21 to 768 dyne sec/cm⁵ (196 ± 192 dyne sec/cm⁵) for the mean and S.d and this was significantly different from the normal group; p(t) < 0.001.Direct measurement of blood viscosity coupled with angiocinedensitometry at rest and after forced vasodilatation should provide an accurate means of determining the relative significance of a stenotic lesion and distal vessel disease in a given patient on blood flow to the leg.     

Deficiency in Clonogenic Endometrial Mesenchymal Stem Cells in Obese Women with Reproductive Failure – a Pilot Study

Objectives

The mechanisms of obesity associated reproductive complications remain poorly understood. Endometrial mesenchymal stem-cells are critical for cyclic renewal and uterine function. Recently, W5C5⁺ cells, with high clonogenicity, capable of producing endometrial stroma in vivo, have been described. We sought to investigate the abundance and cloning efficiency of W5C5⁺ and W5C5⁻ endometrial cells in relation to Body Mass Index, age and reproductive outcome.

Design

W5C5⁺ and W5C5⁻ cells were purified from mid-luteal endometrial biopsies (n = 54) by magnetic bead separation and subjected to in vitro colony-forming assays.

Results

First trimester pregnancy losses were significantly higher in obese subjects (n = 12) compared to overweight (n = 20) and subjects with normal Body Mass Index (n = 22) (P<0.05, P<0.01, respectively). W5C5⁺ cells (%) were significantly lower in obese subjects compared to subjects with normal Body Mass Index (P<0.05). W5C5⁺ cloning efficiency was significantly lower in obese subjects compared to overweight and subjects with normal Body Mass Index (P<0.05, respectively). W5C5⁻ cloning efficiency was significantly lower in obese subjects compared to subjects with normal Body Mass Index (P<0.05). Body Mass Index was significantly negatively correlated with W5C5⁺ cloning efficiency and W5C5⁻ cloning efficiency (P<0.01, respectively), and positively correlated with first trimester loss (P<0.01). We found no significant results with age (P>0.05).

Conclusions

Our observations suggest that the regenerative capacity and plasticity of the endometrium of obese women is suboptimal, which in turn may account for the increased risk of reproductive complications associated with obesity.     

Calpain 8/nCL-2 and Calpain 9/nCL-4 Constitute an Active Protease Complex,G-Calpain,Involved in Gastric Mucosal Defense

Calpains constitute a superfamily of Ca²⁺-dependent cysteine proteases, indispensable for various cellular processes. Among the 15 mammalian calpains, calpain 8/nCL-2 and calpain 9/nCL-4 are predominantly expressed in the gastrointestinal tract and are restricted to the gastric surface mucus (pit) cells in the stomach. Possible functions reported for calpain 8 are in vesicle trafficking between ER and Golgi, and calpain 9 are implicated in suppressing tumorigenesis. These highlight that calpains 8 and 9 are regulated differently from each other and from conventional calpains and, thus, have potentially important, specific functions in the gastrointestinal tract. However, there is no direct evidence implicating calpain 8 or 9 in human disease, and their properties and physiological functions are currently unknown. To address their physiological roles, we analyzed mice with mutations in the genes for these calpains, Capn8 and Capn9. Capn8^−/− and Capn9^−/− mice were fertile, and their gastric mucosae appeared normal. However, both mice were susceptible to gastric mucosal injury induced by ethanol administration. Moreover, the Capn8^−/− stomach showed significant decreases in both calpains 9 and 8, and the same was true for Capn9^−/−. Consistent with this finding, in the wild-type stomach, calpains 8 and 9 formed a complex we termed “G-calpain,” in which both were essential for activity. This is the first example of a “hybrid” calpain complex. To address the physiological relevance of the calpain 8 proteolytic activity, we generated calpain 8:C105S “knock-in” (Capn8^CS/CS) mice, which expressed a proteolytically inactive, but structurally intact, calpain 8. Although, unlike the Capn8^−/− stomach, that of the Capn8^CS/CS mice expressed a stable and active calpain 9, the mice were susceptible to ethanol-induced gastric injury. These results provide the first evidence that both of the gastrointestinal-tract-specific calpains are essential for gastric mucosal defense, and they point to G-calpain as a potential target for gastropathies caused by external stresses.     

Association of Aminoacyl-tRNA Synthetases Gene Polymorphisms with the Risk of Congenital Heart Disease in the Chinese Han Population

Aminoacyl-tRNA synthetases (ARSs) are in charge of cellular protein synthesis and have additional domains that function in a versatile manner beyond translation. Eight core ARSs (EPRS, MRS, QRS, RRS, IRS, LRS, KRS, DRS) combined with three nonenzymatic components form a complex known as multisynthetase complex (MSC).We hypothesize that the single-nucleotide polymorphisms (SNPs) of the eight core ARS coding genes might influence the susceptibility of sporadic congenital heart disease (CHD). Thus, we conducted a case-control study of 984 CHD cases and 2953 non-CHD controls in the Chinese Han population to evaluate the associations of 16 potentially functional SNPs within the eight ARS coding genes with the risk of CHD. We observed significant associations with the risk of CHD for rs1061248 [G/A; odds ratio (OR) = 0.90, 95% confidence interval (CI) = 0.81–0.99; P = 3.81×10⁻²], rs2230301 [A/C; OR = 0.73, 95%CI = 0.60–0.90, P = 3.81×10⁻²], rs1061160 [G/A; OR = 1.18, 95%CI = 1.06–1.31; P = 3.53×10⁻³] and rs5030754 [G/A; OR = 1.39, 95%CI = 1.11–1.75; P = 4.47×10⁻³] of EPRS gene. After multiple comparisons, rs1061248 conferred no predisposition to CHD. Additionally, a combined analysis showed a significant dosage-response effect of CHD risk among individuals carrying the different number of risk alleles (P _trend = 5.00×10⁻⁴). Compared with individuals with “0–2” risk allele, those carrying “3”, “4” or “5 or more” risk alleles had a 0.97-, 1.25- or 1.38-fold increased risk of CHD, respectively. These findings indicate that genetic variants of the EPRS gene may influence the individual susceptibility to CHD in the Chinese Han population.